Research On Aerosol Particle Type Identification And Its Temporal And Spatial Characteristics Based On Multi-source Observation Information

Atmospheric aerosol is a dispersion system composed of various solid and liquid particles suspended in the air,and is an important part of the earth-atmosphere system.Aerosol particles can absorb and scatter short-wave solar radiation and long-wave radiation from the earth,and can also act as condensation nuclei to change the micro-physical characteristics of clouds,thereby affecting the earth’s radiation budget and the temporal and spatial distribution of solar energy.In addition,aerosol particles can also affect the optical remote sensing detection signal through the process of absorption and scattering,resulting in increased background noise and decreased target signal.Because aerosol particles have a high degree of temporal and spatial anomaly,and the radiation properties of different types of aerosol particles are significantly different,it is of great significance to quickly identify the types of aerosol particles and characterize their temporal and spatial distribution rules in the research of aerosol radiation and climate effects,solar energy prediction and effectiveness Utilization,remote sensing of resources and target detection.The seasonal variation characteristics of aerosol optical thickness,single scattering albedo,particle spectrum distribution and other physical parameters in Harbin are obtained based on multi-source observation information including ground-based solar photometer,VIIRS satellite and aerosol particle sampling.Using AERONET global data,the accuracy of VIIRS Deep Blue algorithm aerosol products was verified,and the spatial distribution and seasonal variation of aerosol optical thickness in Northeast China were analyzed.Aerosol particles in spring Harbin were collected and analyzed,and the main sources of the aerosol particles were analyzed by factor analysis.Four aerosol type classification methods including AOD440-AE440-870 、AE440-870-SSA440 、 FMF440-SSA440 and SAE440-670-AAE440-670 were compared at typical AERONET sites,and the differences together with the correlation of aerosol types in these classification methods were explored.Based on ground-based and satellite observation results at Harbin in the spring of 2017,the day-to-day differences of the four classification methods were studied,and the reliability of the aerosol type optical classification method was discussed with the help of particle sampling and offline analysis.The results show that the classification results of the four methods show good consistency.The optical classification method of aerosol type can capture typical aerosol types,but it cannot accurately describe the changes of aerosol components.A statistical method for determining the threshold of background aerosol optical thickness was established,and the best threshold distribution of background aerosol optical thickness on a global scale was obtained.On this basis,the AOD-AE identification method was optimized and the distribution and seasonal variation of typical aerosol particle types between 2013 and 2020 in East Asia were analyzed.With long-term data from AERONET,the radiation properties of typical aerosol particles in China were summarized.It is found that dust aero sols mainly appeared in northwestern China,while urban industrial/biomass-burning aerosols mainly appeared in eastern and central China;the proportion of background aerosols in northwest and northeastern regions was low in spring and summer while high in autumn and winter,and the proportion of background aerosol in the southeastern provinces was high in summer and autumn and low in spring and winter.Finally,an inversion method of aerosol modal complex refractive index is developed and the regional characteristics of the complex refractive index of modal aerosol particles in China are obtained,and the inversion deviations of the real part of the refractive index of fine mode and coarse mode particles are 0.32%±0.64% and0.28%±0.56%,respectively,and the inversion deviations of the imaginary part of the refractive index of fine mode and coarse mode particles are was-2.11%±11.59% and-8.4%±26.42%,respectively.A multi-regression calculation method of surface PM2.5concentration based on aerosol particle type identification is proposed,and it is pointed out that aerosol particle type identification method can effectively improve the calculation accuracy of surface PM2.5 concentration.